Question

Organism 'X' is a multicellular, heterotrophic, eukaryote with a chitinous cell wall. In which kingdom will you place it?

• A. Monera
• B. Animalia
• C. Protista
• D. Fungi

Hint:

Cell wall composition is a major diagnostic tool: Plants = Cellulose, Fungi = Chitin, Bacteria = Peptidoglycan, Animals = No cell wall.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept: R.H. Whittaker's five-kingdom classification system categorizes organisms based on cell structure, body organization, mode of nutrition, and evolutionary relationships.
Step 2: Key Formula or Approach: Use the given traits (multicellular, heterotrophic, eukaryotic, chitinous wall) as a diagnostic checklist to isolate the correct kingdom.
Step 3: Detailed Explanation:
Let's evaluate the options based on the characteristics of organism 'X':
- Monera: Consists of strictly prokaryotic organisms (bacteria). 'X' is a eukaryote, so this is ruled out.
- Protista: Consists of primarily unicellular eukaryotes. While some can have cell walls, they are usually cellulosic or silicaceous. Since 'X' is multicellular, this is ruled out.
- Animalia: Consists of multicellular, heterotrophic eukaryotes. However, animal cells completely lack a cell wall. Thus, this is ruled out.
- Fungi: Consists of multicellular (mostly), heterotrophic (saprophytic/parasitic) eukaryotes. Most distinctively, they possess a rigid cell wall predominantly made of a complex polysaccharide called chitin.
All given traits perfectly align with the Kingdom Fungi.
Step 4: Final Answer: Organism 'X' should be placed in Kingdom Fungi.